One of my personal favorites: ¡Que oso!

Literally "what a bear!"

Used to express embarrassment :) 

ex:

-...y después me di cuenta que ella saludaba a la persona detras de mi! (And then I realized she was waving at the person behind me!)

- ay no, que oso! (Embarrassing!)

"¡Que hueva!" "Me lleva la que me trajo" and "Puta madre" are some of the most popular Mexican slang, everyone in the country would understand you by saying these phrases, which mean literally:

1.- "Que hueva!". Literally, "what an egg!" Meaning something boring to do... It is used when someone invites you to do something, like watch a movie, go for a coffee, etc, and you just don't want to do it because you feel so lazy in that moment, then you say: "Noooo, ¡que hueva!". That'd be enough to keep him/her away until the next day! Lol

2.- "Me lleva la que me trajo" OR you can use "me lleva la chingada" instead, both means the same, the difference is their rudeness level, the first one is without cursing, and I think you shouldn't say the second one in front of your kids!. It means literally "Who brought me here is now taking me away... I know, it has no sense if you say it like that, but, what really means is a feeling; angry, rage, disgust, just because something bad happened to you... And, it's your fault! Maybe if you forgot your wallet in any public place, left your car keys inside the CAR or just screwed a magnificent day up with your boy/girlfriend you can always say "¡Me lleva la chingada!"

3.- "Puta madre!" This is probably one of the most rude Mexican slangs, and it literally means "whore mother!" But be cool, it has nothing to do with YOUR mother, maybe with someone else's mother but probably it's just rage... What it really means is "Fuck!" And I bet you know very well its use ;)

Hope this help you! Regards

Martín Del Ángel

Es difícil porque cada país tiene sus propios modismos (slang), tendrías que averiguar los más usados por país. Acá encontré los modismos chilenos (chilenismos): http://www.natalislang.com/english/slang.html

Gabby: también me gustan el slang de México, creo que son los mejores, y además graciosos: guey, chinga, órale.

¡Hola, "tía"!  En España es muy habitual el saludar así a los amigos. ¡Hola, tío! si es un chico o "tíos" si son varias personas; sería el equivalente a "guys".

Cuando tu jefe en el trabajo te pide que hagas algo que supone mucho esfuerzo pero que no puedes rechazar, se suele decir "!Qué marrón!"

¡Qué pasada! lo decimos cuando sucede algo que te deja impresionado o con la boca abierta. Por ejemplo: Estuve en las cataratas del Niágara. ¡Qué pasada!

y muchos más... Espero que estas expresiones te hayan gustado.

bueno, "me piro" (I must go)

I like this, No pasa nada.